Concrete is an amalgam of various materials, including water, aggregate (e.g., sand and gravel), and cement, and may include fly ash, fiberglass, chemicals and other additives depending upon the concrete processing plant's abilities and the intended end uses. Concrete is commonly transported to a construction site in concrete mixing transport trucks. The concrete within the delivery vehicles can be loaded at a concrete ready mix facility and prepared and retained within a large rotatable mixing drum. During transportation within the mixing drum, the concrete is in a wet, relatively fluid state. More recently volumetric delivery trucks have come into use where the various separate and unmixed concrete ingredients are separately stored in the truck and are mixed together at the job site as needed to provide the perfect quantity and quality of cement as required.
Regardless of how the concrete is made and delivered, at the construction site, the wet concrete mixture is typically gravitated from the delivery vehicle via pour chutes, which includes a main chute that extends downwardly from an exit of the drum or the concrete feeder, a flop over chute that is hinged to the distal end of the main chute, and sometimes chute extensions. The wet concrete fed from the chutes is poured either directly into the forms at the job site, or is channeled into a concrete pump.
After the concrete mixture has been poured from the delivery vehicle, wet concrete mixture commonly continues to adhere to the pour chutes. In the past, it was common practice for contractors and concrete delivery drivers to hose off the remaining wet concrete mixture on the chutes (and even inside the drum) and allow the now diluted concrete to run onto the ground, onto the street, road, or storm drains systems. However, the rinse water used to clean the pour chutes is considered a groundwater contaminant, can cause substantial damage to storm drain systems, and it more or less universally prohibited across the U.S. and many foreign countries. Consequently, environmental laws generally prohibit the disbursal of such rinse waters and runny concrete onto the ground or at the construction side, unless it is deposited in special receiving pools, tanks, and the like. All such rinse waters must be recouped and recycled without being allowed to flow into streets, storm drains or gutters or allowed to percolate into the soil.
Indeed, one way of dealing with concrete mixture rinse waters at large construction sites is to deposit such rinse waters in a prefabricated lined evaporation pit. The construction of a prefabricated evaporation pit at smaller commercial and residential construction sites is not practical, however. U.S. Pat. Nos. 5,741,065, 6,155,277 and 6,354,439 disclose a variety of equipment for allowing the removal of concrete chute rinse water in the delivery vehicle. However, each such proposed equipment requires the use of expensive and bulky hydraulic, pneumatic or electrical components which must be carried on the delivery vehicle. Such hydraulic or electrical components are expensive to purchase and maintain and awkward to carry on the delivery vehicle. Also, such hydraulic, pneumatic or electrical components leave the driver of the delivery vehicle vulnerable to hydraulic, pneumatic and electrical system failures which would prevent use of the equipment at the construction site. Still further, proposed equipment in the prior art frequently suffers from leakage of contaminated water during the disconnecting of hoses from collection vessels. Finally, several of the proposed equipment requires the use of the vehicle's mixing drum to store the recovered rinse water. Storing such rinse water in the mixing drum can adversely affect the integrity of the next load of concrete mixture prepared and transported within the mixing drum, unless the rinse water is thoroughly drained from the mixing drum prior to the preparation of the next batch of concrete mixture. From a practical standpoint, this is a major disadvantage of such proposed equipment because there is a strong temptation among individual concrete mixture preparation personnel to reuse the rinse water (already in the mixing drum) rather than to take the time to thoroughly drain and reconstitute the rinse water and to replace it in the mixing drum with fresh water.
With this in mind, the inventor previously invented and patented as U.S. Pat. No. 7,117,995 a concrete reclamation apparatus. This prior invention is useful for in the separation of solids from a diluted, wet, concrete mixture. This prior device includes (a) a free-standing first container with a drain port and a top opening, (b) a strainer disposed within the first container, (c) a drain port shut-off valve, (d) a second container capable of providing a reservoir for recovered liquid, and (e) a transfer conduit (a hose) for allowing effluent from the drain port of the first container to be gravity feed into the second container. While Applicant's prior system does provide excellent utility, its use requires numerous steps, as follows. A user will need to detach the free-standing first container from a truck mounted rack on hang in on the end of the concrete chute (with provided hooks), connect the transfer conduit between the free-standing first container and the second container (typically retained on the truck), and wash concrete debris on the chutes into the first container. Thereafter, the first container is elevated by raising the pour chute until the drain port of the first container is higher in elevation than the inlet port of the second container. At this point, the first container drain port shut-off valve is opened and the liquid effluent within the second portion of the first container is allowed to gravitate from the first container to the second container. After the first container has been drained, and all effluent has flowed from the first container to the second container via the transfer conduit, the drain port shut-off valve is closed, and the transfer conduit is disconnected from the two containers and stored away. At this point, the user will disengage the free-standing first container from the end of a chute and re-secure it on the concrete truck.
All of these steps require time, effort, and care. Users will need to exercise caution to avoid overfilling the second container since if it is overfilled, the transfer conduit will be full of effluent and this will need to be specially handled to avoid spillage. If more rinse water is needed than is capable of being stored in second container, user may choose to retainer some of the resulting effluent in the first container. If this is the case, a worker will need to lift and move what can be a very heavy effluent and aggregate filled first container from the end of the chute, and reposition it on the truck.
Accordingly, there is a need for a concrete reclamation apparatus which avoids the aforementioned problems in the prior art in an efficient and inexpensive manner.